Effect of intermittent fasting on physiology and gut microbiota in presenium rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of intermittent fasting on metabolize and gut microbiota in obese presenium rats fed with high-fat-sugar-diet.</p><p><b>METHODS</b>We fed the Wistar rats with high-fat and high-sugar diet to induce adiposity, and the rats for intermittent fasting were selected base on their body weight. The rats were subjected to fasting for 72 h every 2 weeks for 18 weeks. OGTT test was performed and fasting blood samples and fecal samples were collected for measurement of TC, TG, HDL-C and LDL-C and sequence analysis of fecal 16S rRNA V4 tags using Illumina. Gut microbial community structure was analyzed with QIIME and LEfSe.</p><p><b>RESULTS</b>After the intervention, the body weight of the fasting rats was significantly lower than that in high-fat diet group (P<0.01). OGTT results suggested impairment of sugar tolerance in the fasting group, which showed a significantly larger AUC than compared with the high-fat diet group (P<0.05). Intermittent fasting significantly reduced blood HDL-C and LDL-C levels (P<0.05) and partially restored liver steatosis, and improved the gut microbiota by increasing the abundance of YS2, RF32 and Helicobacteraceae and reducing Lactobacillus, Roseburia, Erysipelotrichaceae and Ralstonia. Bradyrhizobiaceae was found to be positively correlated with CHOL and HDL-C, and RF39 was inversely correlated with the weight of the rats.</p><p><b>CONCLUSION</b>Intermittent fasting can decrease the body weight and blood lipid levels and restore normal gut microbiota but can cause impairment of glucose metabolism in obese presenium rats.</p>

Distribution characteristics of trimethylamine N-oxide and its association with gut microbiota / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the distribution of trimethylamine N-oxide (TMAO) in healthy adults with different risk factors and explore its association with gut microbiota.</p><p><b>METHODS</b>We collected fasting blood samples and fresh fecal samples from 181 subjects without atherogenesis in the carotid arteries. Plasma TMAO levels of the subjects were determined using stable isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS). The fecal DNA was extracted, and the 16S rRNA V4 tags were amplified and sequenced by Illumina HiSeq 2000. The association between TMAO and classical cardiovascular risk factors were analyzed. Gut microbial community structure was analyzed with QIIME, and LEfSe was used to identify the biomarkers.</p><p><b>RESULTS</b>The median (IQR) TMAO level was 2.66 (1.96-4.91) µmol/L in the subjects. TMAO level was significantly correlated with body mass index and operational taxonomic units (OTU). Individuals with high TMAO levels were found to have abundant Clostridiales, Phascolarctobacterium, Oscillibacter, and Alistipes but less abundant Anaerosprobacter.</p><p><b>CONCLUSION</b>Chinese subjects have in general low levels of TMAO. TMAO levels are not significantly correlated with the classical cardiovascular risk factors or the gut microbial structures.</p>